Variability in Dosing Rate (and amount)

Dear Users, I hope that someone can suggest a paper or method for addressing an issue with which I am grappling. I am working on a mouse toxicokinetic study that has two basic cohorts. One received a bolus gavage dose of known dose and time. The other was dosed by drug-laden chose. The chow and thus drug ingested was measured, usually daily in the morning, but sometimes after 2-3 days. The "daily dose" of chow was averaged over the 12 hours of the daily dark period in which the animals were considered to be eating their chow. 2-3 blood samples were obtained from each animal, and the basic 2 compartmental SEAM IMP method is converging well on the gavage-only data. Can the group suggest how to address the uncertainty in the rate of dosing over the 12 hour dark period? Of additional concern, hard to deal with, is the potential that nightly chose ingestion varied over a series of 1-3 days. I don't think that the 12 August 2020 thread on a random effect on ALAG applies to this case. Many thanks. Paul Paul Hutson, PharmD, BCOP Professor UWisc School of Pharmacy T: 608.263.2496 F: 608.265.5421